Diane Style Casserole

Indulge in the rich and savory flavors of a Diane Style Casserole, a hearty dish that brings the classic steak Diane into cozy casserole form. Tender slices of seared beef sirloin are paired with caramelized onions, earthy cremini mushrooms, and a luscious cream-based sauce infused with Dijon mustard and Worcestershire sauce. Tossed with egg noodles and crowned with a golden layer of Parmesan cheese, this casserole is baked to perfection for a warm, satisfying meal. Perfect for weeknight dinners or family gatherings, this recipe comes together in just an hour and serves six. Serve with a sprinkle of fresh parsley for a touch of freshness that balances the dish’s bold, comforting flavors. Keywords: Diane Style Casserole, beef casserole, creamy mushroom sauce, steak Diane, easy dinner ideas, baked noodle casserole, hearty comfort food.

Nutriscore Rating: 68/100

Prep Time:20 mins

Cook Time:40 mins

Total Time:60 mins

Servings: 6

Ingredients

• 1 lb beef sirloin steak
• 2 tbsp unsalted butter
• 1 tbsp olive oil
• 1 medium yellow onion, diced
• 2 garlic cloves, minced
• 8 oz cremini mushrooms, sliced
• 1.5 cups beef stock
• 0.5 cup heavy cream
• 1 tbsp Dijon mustard
• 2 tsp Worcestershire sauce
• 2 tbsp fresh parsley, chopped
• 2 tbsp all-purpose flour
• 12 oz egg noodles
• 0.5 cup grated Parmesan cheese
• 1 tsp salt
• 0.5 tsp black pepper

Directions

Step 1

Preheat your oven to 375°F (190°C) and grease a large casserole dish lightly with butter or cooking spray.

Step 2

Bring a large pot of salted water to a boil and cook the egg noodles according to package instructions. Drain and set aside.

Step 3

In a large skillet, heat 1 tablespoon of butter and the olive oil over medium-high heat. Season the beef sirloin steak with salt and black pepper, then sear it on each side for about 2-3 minutes until browned. Remove from the skillet and let rest on a cutting board.

Step 4

In the same skillet, lower the heat to medium and add the remaining 1 tablespoon of butter. Sauté the diced onion until softened, about 3-4 minutes. Stir in the minced garlic and cook for an additional minute.

Step 5

Add the sliced mushrooms to the skillet and cook until they release their juices and begin to brown, about 5-6 minutes.

Step 6

Sprinkle the flour over the mushroom mixture and stir to combine. Cook for 1 minute to remove the raw flour taste, then gradually pour in the beef stock, stirring constantly to create a smooth sauce.

Step 7

Stir in the heavy cream, Dijon mustard, Worcestershire sauce, and freshly chopped parsley. Simmer the sauce for 5-7 minutes until slightly thickened. Taste and adjust seasoning with additional salt and pepper if needed.

Step 8

Thinly slice the seared beef against the grain and add it to the sauce. Stir to coat the beef in the mushroom sauce.

Step 9

In a large mixing bowl, combine the cooked egg noodles with the beef and sauce mixture. Toss to evenly combine, then transfer the mixture into the prepared casserole dish.

Step 10

Sprinkle the grated Parmesan cheese evenly over the top of the casserole.

Step 11

Bake in the preheated oven for 20-25 minutes until the casserole is heated through and the cheese is melted and golden brown.

Step 12

Remove from the oven and let cool for 5 minutes before serving. Garnish with additional fresh parsley, if desired. Enjoy!

Nutrition Facts

Serving size	(1726.0g)

Amount per serving	% Daily Value*
Calories	2315.1

Total Fat 126.4g	0%
Saturated Fat 56.0g	0%
Polyunsaturated Fat 1.4g
Cholesterol 576.2mg	0%
Sodium 5201.6mg	0%
Total Carbohydrate 120.2g	0%
Dietary Fiber 9.4g	0%
Total Sugars 11.8g
Protein 164.6g	0%

Vitamin D 23.0IU	0%
Calcium 661.9mg	0%
Iron 18.6mg	0%
Potassium 2845.7mg	0%

*The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.

Source of Calories

Fat: 50.0%

Protein: 28.9%

Carbs: 21.1%